Extensive experiments in this laboratory have shown that it is feasible to guide magnetically-tipped catheters selectively through the canine common carotid tree, and to magnetically fix the tip at a preselected destination. We have shown in the dog that it is possible to obliterate experimental aneurysms and arteriovenous anomalies by using this magnetically guided catheter system to deliver agents or special tips to the morbid area. In conjunction with the Francis Bitter National Magnet Laboratory at the Massachusetts Institute of Technology, we propose to finalize a catheter and magnet system that would achieve these capabilities in man.